Add browser rendering faq

Author: danielgek

src/content/docs/browser-rendering/changelog.mdx

@@ -4,7 +4,7 @@ title: Changelog
 changelog_file_name:
   - browser-rendering
 sidebar:
-  order: 8
+  order: 9
 head: []
 description: Review recent changes to Worker Browser Rendering.
 ---

src/content/docs/browser-rendering/faq.mdx

@@ -0,0 +1,47 @@
+---
+title: FAQ
+pcx_content_type: faq
+sidebar:
+  order: 8
+head:
+  - tag: title
+    content: Frequently asked questions about Cloudflare Browser Rendering
+---
+
+import { GlossaryTooltip } from "~/components";
+
+## Common issues
+
+
+
+### Code generation from strings disallowed for this context while using an Xpath selector
+
+Currently it's not possible to use Xpath to select elements since this poses a security risk to Workers
+
+As an alternative try to use a css selector or `page.evaluate`
+
+```ts
+const innerHtml = await page.evaluate(() => {
+	return (
+		// @ts-ignore this runs on browser context
+		new XPathEvaluator()
+			.createExpression("/html/body/div/h1")
+			// @ts-ignore this runs on browser context
+			.evaluate(document, XPathResult.FIRST_ORDERED_NODE_TYPE).singleNodeValue
+			.innerHTML
+	);
+});
+```
+
+:::note
+
+Keep in mind that `page.evaluate` can only return primitive types like strings, numbers, etc.
+
+Returning an `HTMLElement` won't work.
+
+:::
+
+### Uncaught (in response) TypeError: Cannot read properties of undefined (reading 'fetch')
+
+Make sure that you are passing your Browser binding to the `puppeteer.launch` api and that you have **workers paid** plan.
+

src/content/docs/browser-rendering/index.mdx

@@ -13,7 +13,7 @@ import { CardGrid, Description, LinkTitleCard, Plan, RelatedProduct } from "~/co
 
 <Description>
 
-Browser automation for [Cloudflare Workers](/workers/). 
+Browser automation for [Cloudflare Workers](/workers/).
 </Description>
 
 <Plan type="workers-paid" />